Effect of maturity stage on sorghum silage production: intake, digestibility, energy partition, and methane production in sheep

Effect of maturity stage on sorghum silage production: intake, digestibility, energy partition, and methane production in sheep | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Effect of maturity stage on sorghum silage production: intake, digestibility, energy partition, and methane production in sheep Marielly Maria Almeida Moura, João Paulo Santos Roseira, Wagner Sousa Alves, and 11 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4523679/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The objective of the study was to evaluate the intake, digestibility, energy partition, and methane production of sheep fed with BRS 610 sorghum silage produced from plants harvested at different stages of maturity. Sorghum was harvested at the milk, soft mass, hard mass, and mature stages of development, corresponding to 100, 107, 114, and 121 days after planting, respectively. Twenty uncastrated adult rams were utilized, with five rams per treatment. There was a linear increase in voluntary intake expressed as a function of metabolic weight for dry matter (DM), organic matter (OM), non-fibrous carbohydrates (NFC), and the NDF/CP ratio. The apparent digestibility of DM and OM increased linearly with increasing plant maturity at harvest. The energy content in sorghum silage exhibited a quadratic effect. No significant effect was observed on methane losses, caloric increment (CI), and enteric methane production. BRS 610 sorghum is recommended to be harvested for silage production when the plants reach the hard dough stage. This results in silage with higher energy values, improved voluntary intake, digestibility, and nitrogen use efficiency, without impacting methane production by animals. Biological sciences/Plant sciences/Plant physiology Biological sciences/Zoology/Animal physiology energy utilization enteric methane harvest maturity respirometry Introduction Sorghum ( Sorghum bicolor (L.) Moench) is one of the main crops used for forage production, especially in tropical conditions 1 . In addition to its favorable characteristics for this purpose, sorghum exhibits greater resistance to water deficit and has lower soil fertility requirements compared to corn. Moreover, it offers the advantage of regrowth potential after harvesting 2 – 4 . The timing of crop harvesting for silage production is a crucial management strategy, as it significantly impacts the fermentative profile, process losses, and the nutritional quality of the silage 5 , 6 . McDonald et al. 7 recommended 300 g kg − 1 dry matter (DM) as the ideal content for producing quality silage. For corn and sorghum, this variable has a positive correlation with grain maturity stage 6 . Notably, there is increasing interest among producers in harvesting forage plants at a more advanced stage of maturity (> 300 g kg − 1 DM), due to several benefits: higher DM yield, increased grain percentage, reduced water transport from the field to the silo, and minimized dry matter loss from decreased effluent production. Additionally, this practice results in greater starch accumulation in the grains 6 , 8 , 9 . Nutritionally, increasing starch content in ruminant diets is suggested as an effective way to reduce methane emissions 10 , 11 , as it promotes changes in the rumen, such as a reduction in pH and greater production of proprionate instead of acetate 12 , thereby reducing the availability of hydrogen for methanogenic bacteria. Despite the accumulation of starch in the grains as maturity advances, the nutritional value of the forage can be compromised, especially in tropical conditions 13 . As forage plants mature, they tend to accumulate more cell wall constituents compared to those in temperate conditions 11 , 13 , 14 . Di Marco et al. 15 highlighted that, under unfavorable meteorological conditions, forage digestibility may be better correlated with cell wall digestibility than with starch content. Additionally, it must be considered that late harvesting of plants can negatively affect the fermentation process due to inadequate compaction, which favors increased porosity and the growth of undesirable microorganisms, such as filamentous fungi 16 . Therefore, our hypothesis is that the maturity stage at the time of harvesting sorghum intended for silage production affects its nutritional value, increasing energy use efficiency and reducing methane production. Additionally, the quantification of the potential for methane emission by ruminants consuming sorghum silage enables the generation of data to be used for the development of inventories on greenhouse gas emissions from agricultural production systems, as well as for the evaluation of mitigation strategies. The objective of this study was to evaluate the voluntary intake, digestibility, energy partition, and methane production of sheep fed with sorghum silage produced from plants harvested at different stages of maturity. Materials and methods Location and silage preparation Forage sorghum ‘BRS 610’ was cultivated at Embrapa Milho e Sorgo, located in the municipality of Sete Lagoas - MG, between the coordinates 19º 28’ S and 44º 15’ W, with average annual rainfall of 1,280 mm. Prior to carrying out the study, all necessary authorizations were obtained from the Brazilian Agricultural Research Corporation (EMBRAPA) for the cultivation and harvesting of sorghum. Sorghum was harvested at different stages of maturity, specifically when the grains were in the milk, soft dough, hard dough and mature stages of development, corresponding to 100, 107, 114, and 121 days after planting, respectively. Subsequently, the plants were chopped using a stationary forage machine, with an average particle size of 1.5 cm, and ensiled at an average density of 600 kg of fresh matter m − 3 in metal drums with a capacity of 200 L, internally lined with polyethylene bags. After compacting and sealing, the drums were transported to the facilities of the Animal Science Department of the UFMG Veterinary School, located in Belo Horizonte, state of Minas Gerais, where they were stored in a protected area at room temperature for 60 days. After this period, samples of sorghum silage were collected for pH and chemical composition analyzes 60 ,as presented in Table 1 . Table 1 Chemical composition (g kg − 1 DM) of sorghum silage harvested at different maturity stages Item Harvest age (Days) - (Grains) 100 107 114 121 Milk Soft dough Hard dough Mature pH 3.88 3.94 4.03 4.11 Dry matter (g kg - 1 FM¹) 235 258 304 339 Organic matter 951 951 954 956 Crude protein 67 68 63 63 Neutral detergent fiber 491 432 434 430 Acid detergent fiber 279 253 251 244 Non-fibrous carbohydrates 447 499 502 503 Ethereal Extract 18 21 20 22 Lignin 21 28 30 48 ¹FM = Fresh matter Animals, experimental design and sample collection Twenty uncastrated adult rams, with an average initial weight of 47.5 kg, were utilized, with five rams assigned to each treatment. The animals were acquired through a donation from a small property located in the municipality. After weighing, deworming, and trimming, the rams were individually housed in metabolic cages (1.50 x 0.80 m) equipped with feeders for silage, water, and salt. The cages were located in the Animal Metabolism and Calorimetry Laboratory – LAMCA, at the School of Veterinary of UFMG. Sorghum silage was provided as the sole feed throughout the trial to meet maintenance requirements, with an intake target of 60–80 g of DM kg − 1 BW 0,75 , as recommended by the NRC 61 . Animal handling procedures were conducted in compliance with the recommendations approved by the Animal Experimentation Ethics Committee (CETEA n° 66/2015), and all methods were carried out in accordance with the relevant guidelines and regulations. The methods employed were also aligned with the Animal Research Reporting In Vivo Experiments (ARRIVE) guidelines for the reporting of animal experiments. The experimental period, aimed at estimating voluntary intake and digestibility, spanned 26 days, including 21 days of adaptation followed by five days of sample collection. During the adaptation phase, sorghum silage was provided ad libitum, twice daily (at 6 am and 4:30 pm). Water was changed daily, and mineral salt was replenished as needed. After the adaptation period, sample collection began. Leftovers feed was weighed daily before the morning feeding to adjust voluntary intake. The amount of feed offered was adjusted to ensure 10 to 20% leftovers in the feeder. Over five consecutive days, samples of both the provided silage and leftovers from each animal were weighed and sampled daily, resulting in a composite sample at the end of the experimental period. These composite samples were stored under refrigeration at -20 ºC. At the end of the experimental period, the animals were weighed. Urine collection was conducted by attaching funnels to the cages and placing a bucket containing 100 mL of hydrochloric acid solution (2N HCl). After collection, the weight and total volume of urine excreted over 24 hours were determined, and a 10% aliquot of the daily volume was extracted and stored in a freezer. Composite sample were created for each animal after five days of collection and stored at -20 ºC for further analysis. To collect feces, plastic boxes were positioned beneath the funnels. Feces were collected in the morning, weighed, and samples representing 20% of the total measured were collected and stored. Respirometry test and energy partition On the 27th day, the respirometry test commenced, lasting 24 hours per fed animal, following the protocol outlined by Rodriguez et al. 62 . Each day, one animal underwent the indirect calorimetry test, with the animal's weight recorded upon entering and exiting the chamber. Respirometry was performed in two stages. In the first stage, gas exchange was measured, and the heat production of the fed animals was calculated. During this stage, sorghum silage was provided once daily, in the morning, before sealing the chamber and commencing gas exchange measurements. In the second stage, the heat production of the sheep was calculated during fasting. Following a 48-h of fasting period, the animals remained inside the respirometric chamber for a period of 24 h, receiving only water. Upon opening the chamber, the volume of urine excreted was measured and stored. The results of gas concentrations were determined as proposed by Chwalibog 63 . Air flow was automatically recorded by ExpeData software, which, based on the difference between the composition of the air entering the chamber and that leaving, calculates the volume (L) of oxygen (O 2 ) consumed, carbon dioxide (CO 2 ) produce, and methane (CH 4 ) produced by animals. Heat production was calculated according to the equation proposed by Brouwer 64 : H (kJ)= (16.2 × O 2 (L)) + (5.02 × CO 2 (L)) − (5.88 × Nu (g)) − (2.17 × CH 4 (L)), where H = heat production and Nu = N from urine. To transform the data into calories, the reference was the value of 1 Joule corresponding to 0.239 calories 65 . The respiratory quotient (RQ) was calculated as the ratio between produced CO 2 (L) and consumed O 2 (L). Digestible energy (DE) values were obtained from the difference between the gross energy (GE) of silage, leftovers and feces. Metabolizable energy (ME) values were obtained from the difference between DE and energy losses in the form of methane and urine. The energy lost in the form of methane was determined using the value of 13.334 kcal g − 1 and density of 0.7143 g L − 1 , as proposed by Cavalcanti et al . 66 . Net energy values were obtained from the difference between ME and energy losses in the form of caloric increment. To calculate the caloric increment, the heat production values observed for the fed animal were considered, with the values observed for the same animal during fasting subtracted. Laboratory analysis Samples of provided silage, leftovers, and feces underwent partial moisture removal in a forced air ventilation oven (55 ºC for 72 h) and were subsequently ground in a Willey mill with 1 mm screen sieves. The contents of DM (INCT-CA G-001/1 and G-003/1), CP (INCT-CA N-001/2), EE (INCT-CA G -004/1), ash (INCT-CA M-001/2), NFC, NDF (INCT-CA F-001/2), ADF (INCT-CA F-003 /2) were analyzed. These analyses included appropriate corrections for ash and proteins for both NDF and ADF (INCT-CA M-002/2 and INCT-CA N-004/2, respectively), following the recommendations described by Detmann et al 60 . Net energy values were determined using a C5001 adiabatic bomb calorimeter (IKA-Werke GmbH & Co. KG, Staufen, Germany), following the method described by Detmann et al. 60 . Urine samples from fed animals were analyzed to estimate gross energy and total nitrogen, while urine samples from fasted animals were analyzed to estimate total nitrogen content using the method proposed by Detmann et al . 60 . The voluntary intake of dry matter of silage was determined by calculating the difference between the amount of silage supplied to the animals and the amount of leftovers in the trough. The intake of nutrient e energy was determined based on the intake of DM, considering the percentage per kg of DM of each nutrient in both the supplied feed and the leftovers. Silage intake and fecal production data were utilized to estimate digestibility coefficients. The apparent digestibility of DM, CP, NDF, and ADF was obtained following the method proposed by Detmann et al . 60 . The values of ingested N, fecal N, and urinary N were utilized to calculate the nitrogen balance, or N retained. The retained N value was obtained by the difference, as described by Pires et al . 14 . Statistical analyzes The data were analyzed using a completely randomized design, with harvest age treated as a fixed effect (T), according to the model: Y ij = µ + T i + e ij Where Yi = response variable; µ = general constant; Ti = effect of harvest age and eij = random error assuming an independent normal distribution, NID (0, σ 2 ). After analysis of variance, when significant differences were observed, orthogonal polynomials were employed to determine whether the harvest age resulted in first or second-order effects on the variables. The critical probability level adopted for type I error was 0.05, and the analysis was conducted using the PROC GLM procedure of SAS version 9.4 (SAS Institute Inc., Cary, NC, USA). Data availability All data generated or analyzed during this study are included in this published article. Results Intake and digestibility of nutrients Voluntary intake of dry matter was not affected (P > 0.05) by the different maturity stages (Table 2 ). However, when expressed as a function of metabolic weight, there was a linear increase in the intake of DM, organic matter (OM), and non-fibrous carbohydrates (NFC), as well as in the neutral detergent fiber/crude protein ratio. The intake of crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) were not significantly affected (P > 0.05) by the harvest age (Table 2 ). Table 2 Voluntary intake and apparent digestibility of nutrients from sorghum silage harvested at different stages of maturity Item¹ Harvest age (days) SEM² Contrast ( P -value)³ 100 107 114 121 Linear Quadratic DM intake, g day − 1 961 1053 1023 1154 35.1 NS NS Intake, g kg − 1 of BW 0,75 day − 1 DM 53 59 58 65 1.10 0.006 NS OM 50 56 55 62 1.50 0.005 NS CP 3.4 3.9 3.5 4.1 0.11 NS NS NDF 26 24 23 26 0.60 NS NS ADF 14 15 14 15 0.34 NS NS NFC 23.6 29.4 29.1 32.6 0.70 0.005 NS NFC/CP ratio 6.9 7.5 8.3 8 0.25 0.003 NS Apparent digestibility, g kg − 1 DM DM 505 528 569 560 8.50 0.003 NS OM 536 555 589 584 7.40 0.003 NS CP 380 453 403 419 11.7 NS NS NDF 400 311 372 365 10.3 NS 0.01 ADF 350 325 361 338 14.1 NS NS ¹DM = dry matter; MO = organic matter; CP = crude protein; NDF = neutral detergent fiber; ADF = acid detergent fiber; NFC = non-fibrous carbohydrates. ²EPM = standard error of the mean. ³NS = not significant. Equation for intake: DM = 0.5x + 3.35, R 2 = 0.84; OM = 0.5x + 0.5, R 2 = 0.84; NFC = 0.3814x − 13.473, R 2 = 0.85; NFC/CP ration = 0.0586x + 1.2029, R 2 = 0.75; Equation for apparent digestibility: DM = 2.9429x + 215.31, R 2 = 0.81; OM = 2.5429x + 285.01, R 2 = 0.85; NDF = 0.4184x 2 − 93.088x + 5514.2, R 2 = 0.43. An increasing linear model was fitted (P 0.05) when silage was produced from plants at different maturity stages. For the apparent digestibility of NDF, a quadratic effect was observed, with a minimum value of 337 g kg − 1 of DM recorded when the plants were harvested at 111 days, followed by an increase in this variable (Table 2 ). Nitrogen balance Ingested and fecal nitrogen concentrations were not affected (P > 0.05) when animals were fed sorghum silage harvested at different maturity stages. However, there was an increase in the concentration of nitrogen retained (NR) as the plants matured (Table 3 ). A quadratic model was fitted (P < 0.05) to the means obtained for urinary nitrogen concentrations and the NR/N ingested ratio, with minimum (0.49 g day − 1 ) and maximum (43.2%) values recorded on days 115 and 116, respectively (Table 3 ). Table 3 Nitrogen (N) balance of sheep fed sorghum silage harvested at different maturity stages Item¹ Harvest age (days) SEM² Contrast ( P -value)³ 100 107 114 121 Linear Quadratic N-ingested, g day − 1 9.9 11.4 9.7 11.5 0.41 NS NS N-fecal, g day − 1 6.1 6.1 5.8 6.7 0.20 NS NS N-urinary, g day − 1 3.1 1 1 1 0.32 0.001 0.006 N-retained, g day − 1 0.7 4.2 4 4.8 0.49 0.001 NS NR/N ingested, % 7 35 40 42 38.9 0.001 0.009 ¹NR = nitrogen retained. ²SEM = standard error of the mean. ³NS = not significant. Equation: N-urinary = 0.0107x 2 − 2.4579x + 141.64, R 2 = 0.93; N-retained = 0.1729x − 15.676, R 2 = 0.71; NR/N ingested = -0.1327x 2 + 30.888x − 1754.2, R 2 = 0.97. Energy partitioning and respirometry A quadratic model was fitted to the gross energy (GE), digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of sorghum silage as a function of the harvest age of the plants. Maximum values of 4644, 2741, 2480, 1645 kcal kg − 1 of DM were recorded at 111, 112, 112, and 114 days, respectively, followed by a subsequent decrease (Table 4 ). Table 4 Energy content (kcal kg − 1 of DM) of sorghum silage harvested at different maturity stages Item¹ Harvest age (days) SEM² Contrast (P-value)³ 100 107 114 121 Linear Quadratic GE 4176 4647 4545 4241 46.1 NS < 0.001 DE 2146 2651 2711 2436 56.7 0.001 < 0.001 ME 1873 2383 2454 2186 58.2 0.001 < 0.001 NE 897 1484 1623 1465 60.1 < 0.001 < 0.001 ¹GE = Gross energy; DE = digestible energy; ME = metabolizable energy; NE = net energy. ²SEM = Standard error of the mean. ³NS = not-significant. Equation: = GE = -3.9541x 2 + 875.18x – 43783, R 2 = 0.96; DE = -3.9796x 2 + 892.78x – 47330, R 2 = 0.99; ME= -3.9694x 2 + 891.66x – 47594, R 2 = 0.99; NE = -3.801x 2 + 866.35x – 47721, R 2 = 0.99. When evaluating energy intake, it was found that the variables showed quadratic behavior (P < 0.05) with increasing plant maturity, except for GE, which showed an increasing linear trend (P < 0.05; Table 5 ). Energy intake expressed in DE, ME, and NE as a function of the harvest age of the plants reached maximum values of 164, 148, and 98.7 kcal kg − 1 of DM at 115, 115, and 116 days, respectively (Table 4 ). A quadratic model was fitted (P < 0.05) to the percentage of energy loss via feces, with a minimum value of 40% recorded on day 114, while energy loss via urine showed a linear decrease (P 0.05) on energy losses via methane and caloric increment (IC) for animals fed silage produced from sorghum harvested at different stages of maturity (Table 5 ). The metabolizability (qm) of animals fed with different sorghum silage exhibited quadratic behavior (P < 0.05), while the efficiency of use of metabolizable energy (km) showed an increasing linear trend, with the efficiency of metabolizable energy use increasing daily as plant maturity advanced (Table 5 ). Table 5 Partition and energy efficiency of sorghum silage harvested at different maturity stages Item¹ Harvest age (days) SEM² Contrast (P-value)³ 100 107 114 121 Linear Quadratic Energy intake (kcal kg − 1 BW 0,75 day − 1 ) GE 221 273 262 276 7.48 0.010 NS DE 113 156 157 159 5.59 0.001 0.010 ME 99.0 141 142 142 5.39 0.001 0.010 NE 47.6 88.0 93.6 94.8 5.27 < 0.001 0.008 Energy loss (% of GEI) Feces 48.7 42.8 40.3 42.6 0.91 0.002 0.007 Urine 1.47 1.22 0.68 0.83 0.01 0.002 NS Methane 5.06 4.56 4.99 5.06 0.17 NS NS Caloric increment 23.4 19.4 18.3 17.0 0.27 NS NS qm 0.45 0.51 0.54 0.52 0.01 0.001 0.006 km 0.48 0.62 0.66 0.67 0.01 0.006 NS ¹EB = Gross energy; ED = digestible energy; EM = metabolizable energy; EL = net energy. GEI = gross energy intake; qm = metabolizability of gross energy (ME/GE); km = efficiency of ME utilization for maintenance; ²SEM = Standard error of the mean. ³NS = not-significant. Equation: GE = 2.2x + 14.9, R 2 = 0.61; DE = -0.2092x 2 + 48.215x − 2614.5, R 2 = 0.94; ME = -0.2143x 2 + 49.214x − 2677.6, R² = 0.94; NE== -0.2x 2 + 46.303x − 2581.2, R² = 0.97; Feces = 0.0418x 2 − 9.5431x + 584.71, R 2 = 0.99; Urine = -0.0351x + 4.9333, R 2 = 0.77; qm = − 0.0004x 2 + 0.0936x − 4.8326, R 2 = 0.99; km = 0.0087x − 0.3554, R 2 = 0.81. There was no effect (P > 0.05) on the enteric production of methane when the animals were fed sorghum silage produced from plants harvested at different stages of maturity. Additionally, there was no effect (P > 0.05) on the other variables obtained in the respirometric test (Table 6 ). Table 6 Respirometry and methane (CH 4 ) production of sheep fed with sorghum silage harvested at different stages of maturity Item¹ Harvest age (days) SEM² Contrast ( P -value) 100 107 114 121 Linear Quadratic CH 4 production CH 4 , g d − 1 15.2 16.5 17.2 18.6 0.68 NS NS CH 4 , g kg − 1 DMI 15.9 15.9 17.0 16.1 0.54 NS NS CH 4 , g kg − 1 DDM 31.7 30.1 30.0 28.8 1.14 NS NS CO 2 production CO 2, L day − 1 424 432 418 403 12.8 NS NS CO 2 , L kg − 1 BW 0,75 23.3 24.1 23.9 22.4 0.5 NS NS O 2 consumption O 2, L day − 1 459 493 463 481 18.3 NS NS O 2 , L kg − 1 BW 0,75 25.2 27.3 26.4 26.7 0.8 NS NS Heat production kcal day − 1 2267 2405 2275 2326 85.1 NS NS kcal kg − 1 BW 0,75 125 134 130 129 3.8 NS NS Respiratory quotient 0.93 0.89 0.91 0.84 0.01 NS NS ¹DMI = dry matter intake; DDM = digestible dry matter; ²SEM = Standard error of the mean. NS = not-significant. Discussion Intake and digestibility of nutrients Dry matter intake is the main factor affecting animal production 17 , 18 , as this fraction of the food contains nutrients (proteins, carbohydrates, lipids, vitamins and minerals). In the present study, the linear increase in the intake of DM and non-fibrous carbohydrates (NFC), expressed as metabolic weight, can be explained by the increase in the concentration of dry matter silage and starch in the grains with advancing maturity 6 , 9 . Starch is the main reserve carbohydrate in cereals and represents around 60–80% of the weight of corn and sorghum grains 19 , 20 , which contributes to the increasing the DM content of the crop 6 , 9 . Corroborating Ward et al . 21 , who demonstrated a relationship between increased sorghum silage intake and increased silage DM content. Additionally, the accumulation of starch in the grains with advancing plant maturity favored the linear increase in the digestibility of DM and organic matter (OM) of the silage, as it is a homopolysaccharide with high ruminal digestibility 22 . Several studies have shown that, during fermentation inside the silo, the protein matrix surrounding the starch granules is solubilized, primarily due to the enzymatic activity of bacteria 23 . This increases the digestibility of DM and starch at the ruminal level 24 , 25 . Despite the increase in voluntary intake (g kg − 1 of BW 0.75 day − 1 ) and digestibility of DM, O 2 consumption and CO 2 production by animals were not affected, as these are directly related variables. Although silage made from plants harvested at 100 days has a numerically higher concentration of NDF compared to other silages, as observed by Hatew et al. 11 , this result did not affect the voluntary intake of this fraction by the animals in the present study. Previous research has demonstrated that dietary NDF concentration negatively correlates with voluntary feed intake by animals due to the physical capacity of the rumen 26 , 27 . As recommended by Mertens 28 , NDF intake by sheep fed almost exclusively on forage (ranging 350–750 g of NDF in DM) is approximately 35 g kg − 1 BW 0,75 d − 1 , which is a higher value than the obtained in this study. As plants mature, the concentration of lignin increases, which has a negative correlation with forage digestibility, as reported in previous studies 29 – 31 . In this study, there was a reduction of approximately 28 g kg − 1 of DM in NDF digestibility when comparing silage produced with plants in the milk stage with silage from plants in the hard dough stage. The DM content of the crop to be ensiled is the main factor in deciding the ideal time for harvesting. DM contents between 300–400 g kg − 1 fresh matter are considered adequate to producing good quality silage 32 . During the fermentation process, forages with low DM levels can favor undesirable fermentations by bacteria of the genus Clostridium , which are responsible for the production of butyric acid and excessive production of ammonia, compromising the nutritional value 32 , 33 and voluntary intake 34 , 35 of the silage, and consequently, animal performance. Another negative aspect is the production of effluent, which not only leads to nutrient loss but also poses an environmental risk 36 . The CP levels observed in the silage, which ranged from 63–68 g kg − 1 DM, indicate that there were no significant losses during fermentation, as these values are close to those recorded in previous studies at the time of harvesting the sorghum plants 37 , 38 . This effect can be confirmed by the intake of CP by the animals, which was not affected by the different sorghum silages provided, as well as the digestibility of this fraction. Teixeira et al. 39 reported intake of CP (4.14 g kg − 1 BW 0.75 day − 1 ) similar to that observed in the present study after feeding ‘BRS 610’ sorghum silage to sheep. It is important to highlight that CP is generally the most expensive nutrient in the diet of ruminants and directly influences voluntary intake, performance, and carcass and meat characteristics of sheep 40 , 41 . Nitrogen (N) balance Nitrogen balance is a parameter used to estimate the losses of this nutrient relative to what was ingested by the animal. In this study, the positive N balance indicates that the CP concentrations provided via silage were able to meet the requirements of these animals 14 , 42 . The lack of effect on N ingested by animals can be explained by the close CP levels recorded in the different silage, which ranged from 63 to 68 g kg − 1 of DM. However, the linear increase in NR with advancing plant maturity indicates better utilization of N when animals were fed silage produced from more mature plants. This result was likely due to an increase in the availability of fermentable carbohydrates in the rumen. NFC levels increased with grain maturation, which influenced nitrogen balance, as reported by Calsamiglia et al. 43 . Synchronizing the supply of energy and protein in a diet is essential to maximize microbial growth, increase N retention, and improve the utilization of protein and energy 42 , 44 , 45 . Energy partitioning and respirometry The energy use efficiency of ruminants must be estimated, as insufficient energy intake can limit animal performance 46 . The linear increase in GE intake by animals fed silage produced from plants at different stages of maturity is a result of the increase in dry matter intake, which is in agreement with the high correlation (r²= 0.99) between these parameters, as reported by Machado et al. 37 and So et al. 47 . As previously mentioned, the accumulation of starch in grains with advancing maturity led to the production of silage with a higher concentration of NFC, which are high-energy compounds 18 . This also resulted in a linear increase in NE intake, which is effectively available energy for animal production 48 . The energy losses found in this study align with the findings of Santos et al. 18 and Pires et al. 14 . These authors concluded that fecal production represented the main source of energy loss, followed by caloric increment, methane production and urine. Therefore, it is necessary to develop nutritional strategies and technologies to improve digestibility and reduce caloric increment, aiming to maximize the energy flow for animal performance 37 . In this regard, the use of heterofermentative bacteria during sorghum ensiling can alter the fermentative profile of the silage, leading to an increase in propionate production 14 , 49 . Propionate is the main gluconeogenic precursor used by ruminants 50 , which consequently enhances the efficiency of metabolic energy use and the net energy content of silage 14 . The metabolizability of GE (qm) involves energy losses in feces, urine, and methane, while the efficiency of use of ME (km) represents the real NE available for the maintenance and performance of the animal, which is influenced by caloric increment (IC) 51 . Energy losses in feces were the most impactful on qm, resulting in low values at the four forage harvest ages. km was higher due to energy losses by CI. Machado et al. 37 , evaluating sorghum hybrids ‘BRS 610’, BR 700, and BRS 655 at three maturation stages, found qm values ranging from 0.42 to 0.52, which are close to those observed in this study. However, the values (0.53 to 0.78) were higher, justified by the lower CI values obtained in their evaluation. Fox et al. 52 highlighted km values ranging from 0.576, for diets with ME of 2.0 Mcal kg − 1 (temperate climate grasses in late flowering), 0.651 for diets with ME of 2.6 Mcal kg − 1 (corn forage), and up to 0.686, for diets with ME of 3.2 Mcal kg − 1 (corn grains). The methane emissions observed in this study agree with the results observed by Machado et al . 37 for sorghum silage and McGeough et al . 53 for corn silage harvested at different maturity stages. The increase in starch concentration, accompanied by a decline of fibrous constituents, can alter rumen fermentation, favoring the production of propionic acid and resulting in a decline in methane formation 12 , 53 , 54 . Hatew et al. 11 suggested that late harvesting of corn could be an effective strategy to reduce methane production in dairy cows without negatively impacting their performance. Ruminants fed diets high in fiber and low in NFC can increase methane emissions 13 . Consequently, these animals present lower performance and a longer production cycle 55 , 56 , compromising the sustainability of production systems 18 . In this study, despite the nutritional changes observed in silage produced from plants at different stages of maturation, these were not significant enough to affect methane production by the animals. This lack of effect could possibly be attributed to the fact that the sheep used in the study were in a maintenance situation (low nutritional demand). However, modifications in the nutritional value of forage could potentially yield different results in animals with high nutritional demands, such as growing sheep and lactating cows 11 , 57 – 59 . Conclusion The ‘BRS 610’ sorghum should be harvested for silage production when the plants have grains in the hard dough stage. This stage ensures the production of roughage with higher energy values, improved voluntary intake, digestibility, and efficiency in nitrogen utilization, without adversely affecting methane production by animals. A practical implication to be considered is the processing of sorghum grains at harvesting. Improper processing can compromise the nutritional value of the silage, particularly the availability of energy for the animal. Declarations Competing interests The authors declare no competing interests Author Contribution Author contributions: J.P.S.R. Writing - original draft, writing - review & editing, W.S.A. Data curation, writing - original draft, writing - review & editing. All authors (Marielly Maria Almeida Moura, João Paulo Santos Roseira, Wagner Sousa Alves, Otaviano de Souza Pires Neto, Edson Hiydu Mizobutsi, Daniel Ananias de Assis Pires, Renê Ferreira Costa, Cinara da Cunha Siqueira Carvalho, Irisléia Pereira Soares de Sousa, Martielle Batista Fernandes, Luciele Barboza de Almeida, Sabrina Gonçalves Vieira de Castro, Diogo Gonzaga Jayme, Lúcio Carlos Gonçalves) reviewed the manuscript. Acknowledgements We thank CNPq, CAPES, INCT-CA, and FAPEMIG for their financial support. Data Availability All data generated or analyzed during this study are included in this published article. References Silvestre, A. M. & Millen, D. D. The 2019 Brazilian Survey On Nutritional Practices Provided By Feedlot Cattle Consulting Nutritionists. R. Bras. Zootec 50, 1–25 (2021). Perazzo, A. F. et al. Agronomic Evaluation of Sorghum Hybrids for Silage Production Cultivated in Semiarid Conditions. Front Plant Sci 8, (2017). Bhattarai, B., Singh, S., West, C. P. & Saini, R. Forage Potential of Pearl Millet and Forage Sorghum Alternatives to Corn under the Water-Limiting Conditions of the Texas High Plains: A Review. Crop, Forage & Turfgrass Management 5, 190058 (2019). Nematpour, A., Eshghizadeh, H. R. & Zahedi, M. Comparing the Corn, Millet and Sorghum as Silage Crops Under Different Irrigation Regime and Nitrogen Fertilizer Levels. Int J Plant Prod 15, 351–361 (2021). Rodrigues, P. H. M., Pinedo, L. A., Meyer, P. M., da Silva, T. H. & Guimarães, I. C. da S. B. Sorghum silage quality as determined by chemical–nutritional factors. Grass and Forage Science 75, 462–473 (2020). Lyons, S. E. et al. Optimal harvest timing for brown midrib forage sorghum yield, nutritive value, and ration performance. J Dairy Sci 102, 7134–7149 (2019). McDonald, P., Henderson, A. R. & Heron, S. J. E. Biochemistry of Silage (Marlow Chalcombe Publications, 1991). Lynch, J. P., O’Kiely, P. & Doyle, E. M. Yield, quality and ensilage characteristics of whole-crop maize and of the cob and stover components: harvest date and hybrid effects. Grass and Forage Sci 67, 472–487 (2012). Terler, G., Resch, R., Gappmaier, S. & Gruber, L. Nutritive value for ruminants of different fresh and ensiled sorghum ( Sorghum bicolor (L.) Moench) varieties harvested at varying maturity stages. Arch Anim Nutr 75, 167–182 (2021). Hristov, A. N. et al. SPECIAL TOPICS - Mitigation of methane and nitrous oxide emissions from animal operations: I. A review of enteric methane mitigation options1. J Anim Sci 91, 5045–5069 (2013). Hatew, B., Bannink, A., van Laar, H., de Jonge, L. H. & Dijkstra, J. Increasing harvest maturity of whole-plant corn silage reduces methane emission of lactating dairy cows. J Dairy Sci 99, 354–368 (2016). Lettat, A., Hassanat, F. & Benchaar, C. Corn silage in dairy cow diets to reduce ruminal methanogenesis: Effects on the rumen metabolically active microbial communities. J Dairy Sci 96, 5237–5248 (2013). Archimède, H. et al. Comparison of methane production between C3 and C4 grasses and legumes. Anim Feed Sci Technol 166–167, 59–64 (2011). Pires, F. P. A. de A. et al. Effect of the Lactiplantibacillus plantarum and Lentilactobacillus buchneri on corn and sorghum silage quality and sheep energy partition under tropical conditions. Grass and Forage Science 78, 224–235 (2023). Di Marco, O. N., Aello, M. S., Nomdedeu, M. & Van Houtte, S. Effect of maize crop maturity on silage chemical composition and digestibility (in vivo, in situ and in vitro). Anim Feed Sci Technol 99, 37–43 (2002). Borreani, G., Tabacco, E., Schmidt, R. J., Holmes, B. J. & Muck, R. E. Silage review: Factors affecting dry matter and quality losses in silages. J Dairy Sci 101, 3952–3979 (2018). Wu, P., Fu, X., Wang, H., Hou, M. & Shang, Z. Effect of Silage Diet (Sweet Sorghum vs. Whole-Crop Corn) and Breed on Growth Performance, Carcass Traits, and Meat Quality of Lambs. Animals 11, 3120 (2021). Santos, F. P. C. et al. Re-ensiling effects on sorghum silage quality, methane emission and sheep efficiency in tropical climate. Grass and Forage Sci 76, 440–450 (2021). Fernandes, T. et al. Effect of amylases and storage length on losses, nutritional value, fermentation, and microbiology of silages of corn and sorghum kernels. Anim Feed Sci Technol 285, 115227 (2022). Hill, H., Slade Lee, L. & Henry, R. J. Variation in sorghum starch synthesis genes associated with differences in starch phenotype. Food Chem 131, 175–183 (2012). Ward, G. M., Boren, F. W., Smith, E. F. & Brethour, J. R. Relation between Dry Matter Content and Dry Matter Consumption of Sorghum Silage. J Dairy Sci 49, 399–402 (1966). Owens, F. N., Zinn, R. A. & Kim, Y. K. Limits to Starch Digestion in the Ruminant Small Intestine1,2. J Anim Sci 63, 1634–1648 (1986). Junges, D. et al. Short communication: Influence of various proteolytic sources during fermentation of reconstituted corn grain silages. J Dairy Sci 100, 9048–9051 (2017). Roseira, J. P. S. et al. Effects of exogenous protease addition on fermentation and nutritive value of rehydrated corn and sorghum grains silages. Sci Rep 13, 7302 (2023). Fernandes, T., Paula, E. M., Sultana, H. & Ferraretto, L. F. Short communication: Influence of sorghum cultivar, ensiling storage length, and microbial inoculation on fermentation profile, N fractions, ruminal in situ starch disappearance and aerobic stability of whole-plant sorghum silage. Anim Feed Sci Technol 266, 114535 (2020). Oba, M. & Allen, M. S. Evaluation of the importance of the digestibility of neutral detergent fiber from forage: Effects on dry matter intake and milk yield of dairy cows. J Dairy Sci 82, 589–596 (1999). Miller, M. D. et al. Influence of fiber degradability of corn silage in diets with lower and higher fiber content on lactational performance, nutrient digestibility, and ruminal characteristics in lactating Holstein cows. J Dairy Sci 104, 1728–1743 (2021). Mertens, D. R. Predicting Intake and Digestibility Using Mathematical Models of Ruminal Function. J Anim Sci 64, 1548–1558 (1987). Sousa, D. O., Murphy, M., Hatfield, R. & Nadeau, E. Effects of harvest date and grass species on silage cell wall components and lactation performance of dairy cows. J Dairy Sci 104, 5391–5404 (2021). Kerley G C Fahey Jr J M Gould E L Iannotti, M. S. Effects of lignification, cellulose crystallinity and enzyme accessible space on the digestibility of plant cell wall carbohydrates in the ruminant. Food Structure 7, 59–65 (1988). Costa, R. F. et al. In situ degradability of dry matter and fibrous fraction of sorghum silage. Acta Sci 38, 171 (2016). Kung, L., Shaver, R. D., Grant, R. J. & Schmidt, R. J. Silage review: Interpretation of chemical, microbial, and organoleptic components of silages. J Dairy Sci 101, 4020–4033 (2018). Santos, A. C. P. dos et al. Productive and metabolic parameters, carcass and meat characteristics of lambs fed sorghum silage treated with urea and Lactobacillus buchneri. Livest Sci 251, 104603 (2021). Wilkins, R. J., Hutchinson, K. J., Wilson, R. F. & Harris, C. E. The voluntary intake of silage by sheep:I. Interrelationships between silage composition and intake. J Agric Sci 77, 531–537 (1971). Rook, A. J. & Gill, M. Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses. Animal Science 50, 425–438 (1990). Gebrehanna, M. M., Gordon, R. J., Madani, A., VanderZaag, A. C. & Wood, J. D. Silage effluent management: A review. J Environ Manage 143, 113–122 (2014). Machado, F. S. et al. Energy partitioning and methane emission by sheep fed sorghum silages at different maturation stages. Arq Bras Med Vet Zootec 67, 790–800 (2015). Faria Júnior, W. G. et al. Effect of grain maturity stage on the quality of sorghum BRS-610 silages. Arq Bras Med Vet Zootec 63, 1215–1223 (2011). Teixeira, A. de M. et al. Intake and digestibility of sorghum (Sorghum bicolor, L. Moench) silages with different tannin contents in sheep. R. Bras. de Zootec. 43, 14–19 (2014). Dabiri, N. & Thonney, M. L. Source and level of supplemental protein for growing lambs1. J Anim Sci 82, 3237–3244 (2004). Saro, C. et al. Effect of Dietary Crude Protein on Animal Performance, Blood Biochemistry Profile, Ruminal Fermentation Parameters and Carcass and Meat Quality of Heavy Fattening Assaf Lambs. Animals 10, 2177 (2020). Almeida, J. C. S. et al. Intake, digestibility, microbial protein production, and nitrogen balance of lambs fed with sorghum silage partially replaced with dehydrated fruit by-products. Trop Anim Health Prod 51, 619–627 (2019). Calsamiglia, S., Ferret, A., Reynolds, C. K., Kristensen, N. B. & van Vuuren, A. M. Strategies for optimizing nitrogen use by ruminants. Animal 4, 1184–1196 (2010). Nocek, J. E. & Russell, J. B. Protein and Energy as an Integrated System. Relationship of Ruminal Protein and Carbohydrate Availability to Microbial Synthesis and Milk Production. J Dairy Sci 71, 2070–2107 (1988). Souza, C. M. et al. Lambs fed cassava silage with added tamarind residue: Silage quality, intake, digestibility, nitrogen balance, growth performance and carcass quality. Anim Feed Sci Technol 235, 50–59 (2018). Brito Neto, A. S. et al. Feed energy utilization by hair sheep: does the 0.82 conversion factor of digestible to metabolizable energy need to be revised? J Agric Sci 161, 734–742 (2023). So, S., Cherdthong, A. & Wanapat, M. Growth performances, nutrient digestibility, ruminal fermentation and energy partition of Thai native steers fed exclusive rice straw and fermented sugarcane bagasse with Lactobacillus , cellulase and molasses. J Anim Physiol Anim Nutr (Berl) 106, 45–54 (2022). Weiss, W. P. Predicting Energy Values of Feeds. J Dairy Sci 76, 1802–1811 (1993). Alves, W. S. et al. Effect of new strains of Lentilactobacillus buchneri as inoculants in sorghum silage on the fermentative profile, aerobic stability, and voluntary intake in lambs. New Zealand J of Agri. Res. 1–17 (2023). Wang, G. Y. et al. Propionate promotes gluconeogenesis by regulating mechanistic target of rapamycin (mTOR) pathway in calf hepatocytes. Animal Nutrition 15, 88–98 (2023). Galvani, D. B. et al. Energy efficiency of growing ram lambs fed concentrate-based diets with different roughage sources. J Anim Sci 92, 250–263 (2014). Fox, D. G. et al. The Cornell Net Carbohydrate and Protein System model for evaluating herd nutrition and nutrient excretion. Anim Feed Sci Technol 112, 29–78 (2004). Mc Geough, E. J. et al. Methane emissions, feed intake, and performance of finishing beef cattle offered maize silages harvested at 4 different stages of maturity1. J Anim Sci 88, 1479–1491 (2010). Sutton, J. D., Cammell, S. B., Phipps, R. H., Beever, D. E. & Humphries, D. J. The effect of crop maturity on the nutritional value of maize silage for lactating dairy cows. 2. Ruminal and post-ruminal digestion. Animal Science 71, 391–400 (2000). Cardoso, A. S. et al. Impact of the intensification of beef production in Brazil on greenhouse gas emissions and land use. Agric Syst 143, 86–96 (2016). Cerri, C. E. P. et al. Reducing Amazon Deforestation through Agricultural Intensification in the Cerrado for Advancing Food Security and Mitigating Climate Change. Sustainability 10, 989 (2018). Jonker, A. et al. Methane emissions changed nonlinearly with graded substitution of alfalfa silage with corn silage and corn grain in the diet of sheep and relation with rumen fermentation characteristics in vivo and in vitro1,2. J Anim Sci 94, 3464–3475 (2016). Van Gastelen, S., Dijkstra, J. & Bannink, A. Are dietary strategies to mitigate enteric methane emission equally effective across dairy cattle, beef cattle, and sheep? J Dairy Sci 102, 6109–6130 (2019). Gislon, G. et al. Milk production, methane emissions, nitrogen, and energy balance of cows fed diets based on different forage systems. J Dairy Sci 103, 8048–8061 (2020). Detmann, E. & Valadares Filho, S. C. On the estimation of non-fibrous carbohydrates in feeds and diets. Arq Bras Med Vet Zootec 62, 980–984 (2010). Moraes, A. et al. Effect of application rate of sodium nitrite and hexamine on the fermentation and the chemical composition of guinea grass silage harvested at different stages of maturity. Anim Feed Sci Technol 302, 115667 (2023). Rodríguez, N. M. et al. A calorimetry system for metabolism trials. Arq Bras Med Vet Zootec 59, 495–500 (2007). Alhadas, H. M., Valadares Filho, S. C., Tedeschi, L. O., Vilela, R. S. R. & Souza, G. A. P. In situ evaluation of dried distillers grains (DDG) and of diets containing different levels of DDG inclusion replacing soybean meal, urea and corn, and development of alternative methods to estimate in vivo digestibility of diets. Livest Sci 253, 104706 (2021). Ferrero, F., Tabacco, E. & Borreani, G. Lentilactobacillus hilgardii Inoculum, Dry Matter Contents at Harvest and Length of Conservation Affect Fermentation Characteristics and Aerobic Stability of Corn Silage. Front Microbiol 12, 1–10 (2021). Hargrove, J. L. History of the Calorie in Nutrition. J Nutr 136, 2957–2961 (2006). Cavalcanti, A. C. et al. Partição da energia e produção de metano em ovinos alimentados com feno de Andropogon Gayanus colhido em três diferentes idades. Revista de la Facultad de Agronomía 118, 102–113 (2019). Additional Declarations No competing interests reported. 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Gerais","correspondingAuthor":false,"prefix":"","firstName":"Lúcio","middleName":"Carlos","lastName":"Gonçalves","suffix":""}],"badges":[],"createdAt":"2024-06-03 18:47:45","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4523679/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4523679/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":66263793,"identity":"547b8693-8f7a-4f62-9b53-394bbf1b2bf1","added_by":"auto","created_at":"2024-10-09 11:09:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1079293,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4523679/v1/56c9bf49-9350-4b92-b92a-f271a268dc70.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of maturity stage on sorghum silage production: intake, digestibility, energy partition, and methane production in sheep","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSorghum (\u003cem\u003eSorghum bicolor\u003c/em\u003e (L.) Moench) is one of the main crops used for forage production, especially in tropical conditions\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. In addition to its favorable characteristics for this purpose, sorghum exhibits greater resistance to water deficit and has lower soil fertility requirements compared to corn. Moreover, it offers the advantage of regrowth potential after harvesting\u003csup\u003e\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe timing of crop harvesting for silage production is a crucial management strategy, as it significantly impacts the fermentative profile, process losses, and the nutritional quality of the silage\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. McDonald \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e recommended 300 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e dry matter (DM) as the ideal content for producing quality silage. For corn and sorghum, this variable has a positive correlation with grain maturity stage\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNotably, there is increasing interest among producers in harvesting forage plants at a more advanced stage of maturity (\u0026gt;\u0026thinsp;300 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DM), due to several benefits: higher DM yield, increased grain percentage, reduced water transport from the field to the silo, and minimized dry matter loss from decreased effluent production. Additionally, this practice results in greater starch accumulation in the grains\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNutritionally, increasing starch content in ruminant diets is suggested as an effective way to reduce methane emissions\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e, as it promotes changes in the rumen, such as a reduction in pH and greater production of proprionate instead of acetate\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e, thereby reducing the availability of hydrogen for methanogenic bacteria.\u003c/p\u003e \u003cp\u003eDespite the accumulation of starch in the grains as maturity advances, the nutritional value of the forage can be compromised, especially in tropical conditions\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. As forage plants mature, they tend to accumulate more cell wall constituents compared to those in temperate conditions\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Di Marco \u003cem\u003eet al.\u003c/em\u003e \u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e highlighted that, under unfavorable meteorological conditions, forage digestibility may be better correlated with cell wall digestibility than with starch content.\u003c/p\u003e \u003cp\u003eAdditionally, it must be considered that late harvesting of plants can negatively affect the fermentation process due to inadequate compaction, which favors increased porosity and the growth of undesirable microorganisms, such as filamentous fungi\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eTherefore, our hypothesis is that the maturity stage at the time of harvesting sorghum intended for silage production affects its nutritional value, increasing energy use efficiency and reducing methane production. Additionally, the quantification of the potential for methane emission by ruminants consuming sorghum silage enables the generation of data to be used for the development of inventories on greenhouse gas emissions from agricultural production systems, as well as for the evaluation of mitigation strategies. The objective of this study was to evaluate the voluntary intake, digestibility, energy partition, and methane production of sheep fed with sorghum silage produced from plants harvested at different stages of maturity.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eLocation and silage preparation\u003c/h2\u003e \u003cp\u003eForage sorghum \u0026lsquo;BRS 610\u0026rsquo; was cultivated at Embrapa Milho e Sorgo, located in the municipality of Sete Lagoas - MG, between the coordinates 19\u0026ordm; 28\u0026rsquo; S and 44\u0026ordm; 15\u0026rsquo; W, with average annual rainfall of 1,280 mm. Prior to carrying out the study, all necessary authorizations were obtained from the Brazilian Agricultural Research Corporation (EMBRAPA) for the cultivation and harvesting of sorghum.\u003c/p\u003e \u003cp\u003eSorghum was harvested at different stages of maturity, specifically when the grains were in the milk, soft dough, hard dough and mature stages of development, corresponding to 100, 107, 114, and 121 days after planting, respectively. Subsequently, the plants were chopped using a stationary forage machine, with an average particle size of 1.5 cm, and ensiled at an average density of 600 kg of fresh matter m\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e in metal drums with a capacity of 200 L, internally lined with polyethylene bags. After compacting and sealing, the drums were transported to the facilities of the Animal Science Department of the UFMG Veterinary School, located in Belo Horizonte, state of Minas Gerais, where they were stored in a protected area at room temperature for 60 days. After this period, samples of sorghum silage were collected for pH and chemical composition analyzes\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e,as presented in Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eChemical composition (g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DM) of sorghum silage harvested at different maturity stages\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eItem\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eHarvest age (Days) - (Grains)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e121\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMilk\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSoft dough\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHard dough\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMature\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDry matter (g kg\u003csup\u003e-\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e FM\u0026sup1;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e235\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e258\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e304\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e339\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOrganic matter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e951\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e951\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e954\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e956\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCrude protein\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeutral detergent fiber\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e491\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e432\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e434\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e430\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAcid detergent fiber\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e279\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e253\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e251\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e244\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-fibrous carbohydrates\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e447\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e499\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e502\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e503\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEthereal Extract\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLignin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u0026sup1;FM\u0026thinsp;=\u0026thinsp;Fresh matter\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eAnimals, experimental design and sample collection\u003c/h2\u003e \u003cp\u003eTwenty uncastrated adult rams, with an average initial weight of 47.5 kg, were utilized, with five rams assigned to each treatment. The animals were acquired through a donation from a small property located in the municipality. After weighing, deworming, and trimming, the rams were individually housed in metabolic cages (1.50 x 0.80 m) equipped with feeders for silage, water, and salt. The cages were located in the Animal Metabolism and Calorimetry Laboratory \u0026ndash; LAMCA, at the School of Veterinary of UFMG.\u003c/p\u003e \u003cp\u003eSorghum silage was provided as the sole feed throughout the trial to meet maintenance requirements, with an intake target of 60\u0026ndash;80 g of DM kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0,75\u003c/sup\u003e, as recommended by the NRC\u003csup\u003e\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e\u003c/sup\u003e. Animal handling procedures were conducted in compliance with the recommendations approved by the Animal Experimentation Ethics Committee (CETEA n\u0026deg; 66/2015), and all methods were carried out in accordance with the relevant guidelines and regulations. The methods employed were also aligned with the Animal Research Reporting \u003cem\u003eIn Vivo\u003c/em\u003e Experiments (ARRIVE) guidelines for the reporting of animal experiments.\u003c/p\u003e \u003cp\u003eThe experimental period, aimed at estimating voluntary intake and digestibility, spanned 26 days, including 21 days of adaptation followed by five days of sample collection. During the adaptation phase, sorghum silage was provided ad libitum, twice daily (at 6 am and 4:30 pm). Water was changed daily, and mineral salt was replenished as needed.\u003c/p\u003e \u003cp\u003eAfter the adaptation period, sample collection began. Leftovers feed was weighed daily before the morning feeding to adjust voluntary intake. The amount of feed offered was adjusted to ensure 10 to 20% leftovers in the feeder. Over five consecutive days, samples of both the provided silage and leftovers from each animal were weighed and sampled daily, resulting in a composite sample at the end of the experimental period. These composite samples were stored under refrigeration at -20 \u0026ordm;C. At the end of the experimental period, the animals were weighed.\u003c/p\u003e \u003cp\u003eUrine collection was conducted by attaching funnels to the cages and placing a bucket containing 100 mL of hydrochloric acid solution (2N HCl). After collection, the weight and total volume of urine excreted over 24 hours were determined, and a 10% aliquot of the daily volume was extracted and stored in a freezer. Composite sample were created for each animal after five days of collection and stored at -20 \u0026ordm;C for further analysis. To collect feces, plastic boxes were positioned beneath the funnels. Feces were collected in the morning, weighed, and samples representing 20% of the total measured were collected and stored.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eRespirometry test and energy partition\u003c/h2\u003e \u003cp\u003eOn the 27th day, the respirometry test commenced, lasting 24 hours per fed animal, following the protocol outlined by Rodriguez \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e\u003c/sup\u003e. Each day, one animal underwent the indirect calorimetry test, with the animal's weight recorded upon entering and exiting the chamber.\u003c/p\u003e \u003cp\u003eRespirometry was performed in two stages. In the first stage, gas exchange was measured, and the heat production of the fed animals was calculated. During this stage, sorghum silage was provided once daily, in the morning, before sealing the chamber and commencing gas exchange measurements. In the second stage, the heat production of the sheep was calculated during fasting. Following a 48-h of fasting period, the animals remained inside the respirometric chamber for a period of 24 h, receiving only water. Upon opening the chamber, the volume of urine excreted was measured and stored.\u003c/p\u003e \u003cp\u003eThe results of gas concentrations were determined as proposed by Chwalibog\u003csup\u003e\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e\u003c/sup\u003e. Air flow was automatically recorded by ExpeData software, which, based on the difference between the composition of the air entering the chamber and that leaving, calculates the volume (L) of oxygen (O\u003csub\u003e2\u003c/sub\u003e) consumed, carbon dioxide (CO\u003csub\u003e2\u003c/sub\u003e) produce, and methane (CH\u003csub\u003e4\u003c/sub\u003e) produced by animals.\u003c/p\u003e \u003cp\u003eHeat production was calculated according to the equation proposed by Brouwer\u003csup\u003e\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e\u003c/sup\u003e: H (kJ)= (16.2 \u0026times; O\u003csub\u003e2\u003c/sub\u003e (L)) + (5.02 \u0026times; CO\u003csub\u003e2\u003c/sub\u003e (L)) \u0026minus; (5.88 \u0026times; Nu (g)) \u0026minus; (2.17 \u0026times; CH\u003csub\u003e4\u003c/sub\u003e (L)), where H\u0026thinsp;=\u0026thinsp;heat production and Nu\u0026thinsp;=\u0026thinsp;N from urine. To transform the data into calories, the reference was the value of 1 Joule corresponding to 0.239 calories\u003csup\u003e\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e\u003c/sup\u003e. The respiratory quotient (RQ) was calculated as the ratio between produced CO\u003csub\u003e2\u003c/sub\u003e (L) and consumed O\u003csub\u003e2\u003c/sub\u003e (L).\u003c/p\u003e \u003cp\u003eDigestible energy (DE) values were obtained from the difference between the gross energy (GE) of silage, leftovers and feces. Metabolizable energy (ME) values were obtained from the difference between DE and energy losses in the form of methane and urine. The energy lost in the form of methane was determined using the value of 13.334 kcal g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and density of 0.7143 g L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, as proposed by Cavalcanti \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e66\u003c/span\u003e\u003c/sup\u003e. Net energy values were obtained from the difference between ME and energy losses in the form of caloric increment. To calculate the caloric increment, the heat production values observed for the fed animal were considered, with the values observed for the same animal during fasting subtracted.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eLaboratory analysis\u003c/h2\u003e \u003cp\u003eSamples of provided silage, leftovers, and feces underwent partial moisture removal in a forced air ventilation oven (55 \u0026ordm;C for 72 h) and were subsequently ground in a Willey mill with 1 mm screen sieves. The contents of DM (INCT-CA G-001/1 and G-003/1), CP (INCT-CA N-001/2), EE (INCT-CA G -004/1), ash (INCT-CA M-001/2), NFC, NDF (INCT-CA F-001/2), ADF (INCT-CA F-003 /2) were analyzed. These analyses included appropriate corrections for ash and proteins for both NDF and ADF (INCT-CA M-002/2 and INCT-CA N-004/2, respectively), following the recommendations described by Detmann \u003cem\u003eet al\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e .\u003c/p\u003e \u003cp\u003eNet energy values were determined using a C5001 adiabatic bomb calorimeter (IKA-Werke GmbH \u0026amp; Co. KG, Staufen, Germany), following the method described by Detmann \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e. Urine samples from fed animals were analyzed to estimate gross energy and total nitrogen, while urine samples from fasted animals were analyzed to estimate total nitrogen content using the method proposed by Detmann \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe voluntary intake of dry matter of silage was determined by calculating the difference between the amount of silage supplied to the animals and the amount of leftovers in the trough. The intake of nutrient e energy was determined based on the intake of DM, considering the percentage per kg of DM of each nutrient in both the supplied feed and the leftovers. Silage intake and fecal production data were utilized to estimate digestibility coefficients. The apparent digestibility of DM, CP, NDF, and ADF was obtained following the method proposed by Detmann \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e. The values of ingested N, fecal N, and urinary N were utilized to calculate the nitrogen balance, or N retained. The retained N value was obtained by the difference, as described by Pires \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analyzes\u003c/h2\u003e \u003cp\u003e The data were analyzed using a completely randomized design, with harvest age treated as a fixed effect (T), according to the model:\u003c/p\u003e \u003cp\u003e \u003cem\u003eY\u003c/em\u003e \u003csub\u003e \u003cem\u003eij\u003c/em\u003e \u003c/sub\u003e\u0026thinsp;=\u0026thinsp;\u0026micro;\u0026thinsp;+\u0026thinsp;T\u003csub\u003e\u003cem\u003ei\u003c/em\u003e\u003c/sub\u003e + e\u003csub\u003e\u003cem\u003eij\u003c/em\u003e\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eWhere Yi\u0026thinsp;=\u0026thinsp;response variable; \u0026micro;\u0026thinsp;=\u0026thinsp;general constant; Ti\u0026thinsp;=\u0026thinsp;effect of harvest age and eij\u0026thinsp;=\u0026thinsp;random error assuming an independent normal distribution, NID (0, σ\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e). After analysis of variance, when significant differences were observed, orthogonal polynomials were employed to determine whether the harvest age resulted in first or second-order effects on the variables. The critical probability level adopted for type I error was 0.05, and the analysis was conducted using the PROC GLM procedure of SAS version 9.4 (SAS Institute Inc., Cary, NC, USA).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eData availability\u003c/h2\u003e \u003cp\u003eAll data generated or analyzed during this study are included in this published article.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eIntake and digestibility of nutrients\u003c/h2\u003e \u003cp\u003eVoluntary intake of dry matter was not affected (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) by the different maturity stages (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e). However, when expressed as a function of metabolic weight, there was a linear increase in the intake of DM, organic matter (OM), and non-fibrous carbohydrates (NFC), as well as in the neutral detergent fiber/crude protein ratio. The intake of crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) were not significantly affected (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) by the harvest age (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eVoluntary intake and apparent digestibility of nutrients from sorghum silage harvested at different stages of maturity\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eItem\u0026sup1;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eHarvest age (days)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSEM\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c11\" namest=\"c10\"\u003e \u003cp\u003eContrast\u003c/p\u003e \u003cp\u003e(\u003cem\u003eP\u003c/em\u003e-value)\u0026sup3;\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e121\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLinear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eQuadratic\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM intake, g day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e961\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e1053\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1154\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e35.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntake, g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of BW\u003csup\u003e0,75\u003c/sup\u003e day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e3.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNDF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eADF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNFC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e29.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e32.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNFC/CP ratio\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApparent digestibility, g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e505\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e528\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e569\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e560\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e536\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e555\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e589\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e584\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e7.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e453\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e403\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e419\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e11.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNDF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e311\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e372\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e365\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e10.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eADF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e350\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e325\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e361\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e338\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e14.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026sup1;DM\u0026thinsp;=\u0026thinsp;dry matter; MO\u0026thinsp;=\u0026thinsp;organic matter; CP\u0026thinsp;=\u0026thinsp;crude protein; NDF\u0026thinsp;=\u0026thinsp;neutral detergent fiber; ADF\u0026thinsp;=\u0026thinsp;acid detergent fiber; NFC\u0026thinsp;=\u0026thinsp;non-fibrous carbohydrates. \u0026sup2;EPM\u0026thinsp;=\u0026thinsp;standard error of the mean. \u0026sup3;NS\u0026thinsp;=\u0026thinsp;not significant. Equation for intake: DM\u0026thinsp;=\u0026thinsp;0.5x\u0026thinsp;+\u0026thinsp;3.35, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.84; OM\u0026thinsp;=\u0026thinsp;0.5x\u0026thinsp;+\u0026thinsp;0.5, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.84; NFC\u0026thinsp;=\u0026thinsp;0.3814x \u0026minus;\u0026thinsp;13.473, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.85; NFC/CP ration\u0026thinsp;=\u0026thinsp;0.0586x\u0026thinsp;+\u0026thinsp;1.2029, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.75; Equation for apparent digestibility: DM\u0026thinsp;=\u0026thinsp;2.9429x\u0026thinsp;+\u0026thinsp;215.31, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.81; OM\u0026thinsp;=\u0026thinsp;2.5429x\u0026thinsp;+\u0026thinsp;285.01, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.85; NDF\u0026thinsp;=\u0026thinsp;0.4184x\u003csup\u003e2\u003c/sup\u003e \u0026minus;\u0026thinsp;93.088x\u0026thinsp;+\u0026thinsp;5514.2, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.43.\u003c/p\u003e \u003cp\u003eAn increasing linear model was fitted (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) to the averages obtained for the apparent digestibility of DM and OM, while CP and ADF were not affected (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) when silage was produced from plants at different maturity stages. For the apparent digestibility of NDF, a quadratic effect was observed, with a minimum value of 337 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of DM recorded when the plants were harvested at 111 days, followed by an increase in this variable (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eNitrogen balance\u003c/h2\u003e \u003cp\u003eIngested and fecal nitrogen concentrations were not affected (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) when animals were fed sorghum silage harvested at different maturity stages. However, there was an increase in the concentration of nitrogen retained (NR) as the plants matured (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e3\u003c/span\u003e). A quadratic model was fitted (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) to the means obtained for urinary nitrogen concentrations and the NR/N ingested ratio, with minimum (0.49 g day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and maximum (43.2%) values recorded on days 115 and 116, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNitrogen (N) balance of sheep fed sorghum silage harvested at different maturity stages\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eItem\u0026sup1;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eHarvest age (days)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSEM\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003eContrast (\u003cem\u003eP\u003c/em\u003e-value)\u0026sup3;\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e121\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eLinear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eQuadratic\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN-ingested, g day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN-fecal, g day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN-urinary, g day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN-retained, g day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNR/N ingested, %\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e38.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.009\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026sup1;NR\u0026thinsp;=\u0026thinsp;nitrogen retained. \u0026sup2;SEM\u0026thinsp;=\u0026thinsp;standard error of the mean. \u0026sup3;NS\u0026thinsp;=\u0026thinsp;not significant. Equation: N-urinary\u0026thinsp;=\u0026thinsp;0.0107x\u003csup\u003e2\u003c/sup\u003e \u0026minus;\u0026thinsp;2.4579x\u0026thinsp;+\u0026thinsp;141.64, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.93; N-retained\u0026thinsp;=\u0026thinsp;0.1729x \u0026minus;\u0026thinsp;15.676, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.71; NR/N ingested = -0.1327x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;30.888x \u0026minus;\u0026thinsp;1754.2, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.97.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eEnergy partitioning and respirometry\u003c/h2\u003e \u003cp\u003eA quadratic model was fitted to the gross energy (GE), digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of sorghum silage as a function of the harvest age of the plants. Maximum values of 4644, 2741, 2480, 1645 kcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of DM were recorded at 111, 112, 112, and 114 days, respectively, followed by a subsequent decrease (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEnergy content (kcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of DM) of sorghum silage harvested at different maturity stages\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eItem\u0026sup1;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eHarvest age (days)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSEM\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003eContrast (P-value)\u0026sup3;\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e121\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eLinear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eQuadratic\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4176\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4647\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4545\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4241\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e46.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2146\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2651\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2711\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2436\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e56.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eME\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1873\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2383\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2454\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2186\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e58.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e897\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1484\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1623\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1465\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e60.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026sup1;GE\u0026thinsp;=\u0026thinsp;Gross energy; DE\u0026thinsp;=\u0026thinsp;digestible energy; ME\u0026thinsp;=\u0026thinsp;metabolizable energy; NE\u0026thinsp;=\u0026thinsp;net energy. \u0026sup2;SEM\u0026thinsp;=\u0026thinsp;Standard error of the mean. \u0026sup3;NS\u0026thinsp;=\u0026thinsp;not-significant. Equation: = GE = -3.9541x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;875.18x \u0026ndash; 43783, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.96; DE = -3.9796x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;892.78x \u0026ndash; 47330, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.99; ME= -3.9694x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;891.66x \u0026ndash; 47594, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.99; NE = -3.801x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;866.35x \u0026ndash; 47721, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.99.\u003c/p\u003e \u003cp\u003eWhen evaluating energy intake, it was found that the variables showed quadratic behavior (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) with increasing plant maturity, except for GE, which showed an increasing linear trend (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Energy intake expressed in DE, ME, and NE as a function of the harvest age of the plants reached maximum values of 164, 148, and 98.7 kcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of DM at 115, 115, and 116 days, respectively (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eA quadratic model was fitted (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) to the percentage of energy loss via feces, with a minimum value of 40% recorded on day 114, while energy loss via urine showed a linear decrease (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) with advancing plant maturity (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e). There was no effect (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) on energy losses via methane and caloric increment (IC) for animals fed silage produced from sorghum harvested at different stages of maturity (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe metabolizability (qm) of animals fed with different sorghum silage exhibited quadratic behavior (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), while the efficiency of use of metabolizable energy (km) showed an increasing linear trend, with the efficiency of metabolizable energy use increasing daily as plant maturity advanced (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePartition and energy efficiency of sorghum silage harvested at different maturity stages\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eItem\u0026sup1;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eHarvest age (days)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSEM\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003eContrast (P-value)\u0026sup3;\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e121\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eLinear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eQuadratic\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"10\" nameend=\"c10\" namest=\"c1\"\u003e \u003cp\u003eEnergy intake (kcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0,75\u003c/sup\u003e day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e221\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e273\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e262\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e276\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e113\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e157\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e159\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eME\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e99.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e141\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e88.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e94.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eEnergy loss (% of GEI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFeces\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e42.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUrine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethane\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCaloric increment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eqm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ekm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026sup1;EB\u0026thinsp;=\u0026thinsp;Gross energy; ED\u0026thinsp;=\u0026thinsp;digestible energy; EM\u0026thinsp;=\u0026thinsp;metabolizable energy; EL\u0026thinsp;=\u0026thinsp;net energy. GEI\u0026thinsp;=\u0026thinsp;gross energy intake; qm\u0026thinsp;=\u0026thinsp;metabolizability of gross energy (ME/GE); km\u0026thinsp;=\u0026thinsp;efficiency of ME utilization for maintenance; \u0026sup2;SEM\u0026thinsp;=\u0026thinsp;Standard error of the mean. \u0026sup3;NS\u0026thinsp;=\u0026thinsp;not-significant. Equation: GE\u0026thinsp;=\u0026thinsp;2.2x\u0026thinsp;+\u0026thinsp;14.9, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.61; DE = -0.2092x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;48.215x \u0026minus;\u0026thinsp;2614.5, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.94; ME = -0.2143x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;49.214x \u0026minus;\u0026thinsp;2677.6, R\u0026sup2; = 0.94; NE== -0.2x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;46.303x \u0026minus;\u0026thinsp;2581.2, R\u0026sup2; = 0.97; Feces\u0026thinsp;=\u0026thinsp;0.0418x\u003csup\u003e2\u003c/sup\u003e \u0026minus;\u0026thinsp;9.5431x\u0026thinsp;+\u0026thinsp;584.71, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.99; Urine = -0.0351x\u0026thinsp;+\u0026thinsp;4.9333, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.77; qm\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.0004x\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;0.0936x \u0026minus;\u0026thinsp;4.8326, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.99; km\u0026thinsp;=\u0026thinsp;0.0087x \u0026minus;\u0026thinsp;0.3554, R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.81.\u003c/p\u003e \u003cp\u003eThere was no effect (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) on the enteric production of methane when the animals were fed sorghum silage produced from plants harvested at different stages of maturity. Additionally, there was no effect (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) on the other variables obtained in the respirometric test (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRespirometry and methane (CH\u003csub\u003e4\u003c/sub\u003e) production of sheep fed with sorghum silage harvested at different stages of maturity\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eItem\u0026sup1;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eHarvest age (days)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSEM\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c10\" namest=\"c9\"\u003e \u003cp\u003eContrast (\u003cem\u003eP\u003c/em\u003e-value)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e114\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e121\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eLinear\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eQuadratic\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCH\u003csub\u003e4\u003c/sub\u003e production\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCH\u003csub\u003e4\u003c/sub\u003e, g d\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCH\u003csub\u003e4\u003c/sub\u003e, g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e16.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCH\u003csub\u003e4\u003c/sub\u003e, g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DDM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e production\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO\u003csub\u003e2,\u003c/sub\u003e L day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e424\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e432\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e418\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e403\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e, L kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0,75\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e22.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO\u003csub\u003e2\u003c/sub\u003e consumption\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO\u003csub\u003e2,\u003c/sub\u003e L day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e459\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e493\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e463\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e481\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e18.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO\u003csub\u003e2\u003c/sub\u003e, L kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0,75\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e26.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeat production\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ekcal day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2267\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2405\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2275\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2326\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e85.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ekcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0,75\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e125\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e134\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e130\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e129\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRespiratory quotient\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eNS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026sup1;DMI\u0026thinsp;=\u0026thinsp;dry matter intake; DDM\u0026thinsp;=\u0026thinsp;digestible dry matter; \u0026sup2;SEM\u0026thinsp;=\u0026thinsp;Standard error of the mean. NS\u0026thinsp;=\u0026thinsp;not-significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eIntake and digestibility of nutrients\u003c/h2\u003e \u003cp\u003eDry matter intake is the main factor affecting animal production\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e, as this fraction of the food contains nutrients (proteins, carbohydrates, lipids, vitamins and minerals). In the present study, the linear increase in the intake of DM and non-fibrous carbohydrates (NFC), expressed as metabolic weight, can be explained by the increase in the concentration of dry matter silage and starch in the grains with advancing maturity\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Starch is the main reserve carbohydrate in cereals and represents around 60\u0026ndash;80% of the weight of corn and sorghum grains\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e, which contributes to the increasing the DM content of the crop\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Corroborating Ward \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e, who demonstrated a relationship between increased sorghum silage intake and increased silage DM content.\u003c/p\u003e \u003cp\u003eAdditionally, the accumulation of starch in the grains with advancing plant maturity favored the linear increase in the digestibility of DM and organic matter (OM) of the silage, as it is a homopolysaccharide with high ruminal digestibility\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e. Several studies have shown that, during fermentation inside the silo, the protein matrix surrounding the starch granules is solubilized, primarily due to the enzymatic activity of bacteria\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. This increases the digestibility of DM and starch at the ruminal level\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e,\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. Despite the increase in voluntary intake (g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of BW\u003csup\u003e0.75\u003c/sup\u003e day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and digestibility of DM, O\u003csub\u003e2\u003c/sub\u003e consumption and CO\u003csub\u003e2\u003c/sub\u003e production by animals were not affected, as these are directly related variables.\u003c/p\u003e \u003cp\u003eAlthough silage made from plants harvested at 100 days has a numerically higher concentration of NDF compared to other silages, as observed by Hatew et al.\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e, this result did not affect the voluntary intake of this fraction by the animals in the present study. Previous research has demonstrated that dietary NDF concentration negatively correlates with voluntary feed intake by animals due to the physical capacity of the rumen\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e,\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. As recommended by Mertens\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e, NDF intake by sheep fed almost exclusively on forage (ranging 350\u0026ndash;750 g of NDF in DM) is approximately 35 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0,75\u003c/sup\u003e d\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which is a higher value than the obtained in this study. As plants mature, the concentration of lignin increases, which has a negative correlation with forage digestibility, as reported in previous studies\u003csup\u003e\u003cspan additionalcitationids=\"CR30\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. In this study, there was a reduction of approximately 28 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of DM in NDF digestibility when comparing silage produced with plants in the milk stage with silage from plants in the hard dough stage.\u003c/p\u003e \u003cp\u003eThe DM content of the crop to be ensiled is the main factor in deciding the ideal time for harvesting. DM contents between 300\u0026ndash;400 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e fresh matter are considered adequate to producing good quality silage\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. During the fermentation process, forages with low DM levels can favor undesirable fermentations by bacteria of the genus \u003cem\u003eClostridium\u003c/em\u003e, which are responsible for the production of butyric acid and excessive production of ammonia, compromising the nutritional value\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e,\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e and voluntary intake\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e,\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e of the silage, and consequently, animal performance. Another negative aspect is the production of effluent, which not only leads to nutrient loss but also poses an environmental risk\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe CP levels observed in the silage, which ranged from 63\u0026ndash;68 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DM, indicate that there were no significant losses during fermentation, as these values are close to those recorded in previous studies at the time of harvesting the sorghum plants\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e. This effect can be confirmed by the intake of CP by the animals, which was not affected by the different sorghum silages provided, as well as the digestibility of this fraction. Teixeira \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e reported intake of CP (4.14 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e BW\u003csup\u003e0.75\u003c/sup\u003e day\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) similar to that observed in the present study after feeding \u0026lsquo;BRS 610\u0026rsquo; sorghum silage to sheep. It is important to highlight that CP is generally the most expensive nutrient in the diet of ruminants and directly influences voluntary intake, performance, and carcass and meat characteristics of sheep\u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e,\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eNitrogen (N) balance\u003c/h3\u003e\n\u003cp\u003eNitrogen balance is a parameter used to estimate the losses of this nutrient relative to what was ingested by the animal. In this study, the positive N balance indicates that the CP concentrations provided via silage were able to meet the requirements of these animals\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe lack of effect on N ingested by animals can be explained by the close CP levels recorded in the different silage, which ranged from 63 to 68 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e of DM. However, the linear increase in NR with advancing plant maturity indicates better utilization of N when animals were fed silage produced from more mature plants. This result was likely due to an increase in the availability of fermentable carbohydrates in the rumen. NFC levels increased with grain maturation, which influenced nitrogen balance, as reported by Calsamiglia \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. Synchronizing the supply of energy and protein in a diet is essential to maximize microbial growth, increase N retention, and improve the utilization of protein and energy\u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e,\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e,\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\n\u003ch3\u003eEnergy partitioning and respirometry\u003c/h3\u003e\n\u003cp\u003eThe energy use efficiency of ruminants must be estimated, as insufficient energy intake can limit animal performance\u003csup\u003e\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe linear increase in GE intake by animals fed silage produced from plants at different stages of maturity is a result of the increase in dry matter intake, which is in agreement with the high correlation (r\u0026sup2;= 0.99) between these parameters, as reported by Machado \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e and So \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e. As previously mentioned, the accumulation of starch in grains with advancing maturity led to the production of silage with a higher concentration of NFC, which are high-energy compounds\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. This also resulted in a linear increase in NE intake, which is effectively available energy for animal production\u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe energy losses found in this study align with the findings of Santos \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e and Pires \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. These authors concluded that fecal production represented the main source of energy loss, followed by caloric increment, methane production and urine. Therefore, it is necessary to develop nutritional strategies and technologies to improve digestibility and reduce caloric increment, aiming to maximize the energy flow for animal performance\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn this regard, the use of heterofermentative bacteria during sorghum ensiling can alter the fermentative profile of the silage, leading to an increase in propionate production\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e. Propionate is the main gluconeogenic precursor used by ruminants\u003csup\u003e\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u003c/sup\u003e, which consequently enhances the efficiency of metabolic energy use and the net energy content of silage\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe metabolizability of GE (qm) involves energy losses in feces, urine, and methane, while the efficiency of use of ME (km) represents the real NE available for the maintenance and performance of the animal, which is influenced by caloric increment (IC)\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. Energy losses in feces were the most impactful on qm, resulting in low values at the four forage harvest ages. km was higher due to energy losses by CI. Machado \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e, evaluating sorghum hybrids \u0026lsquo;BRS 610\u0026rsquo;, BR 700, and BRS 655 at three maturation stages, found qm values ranging from 0.42 to 0.52, which are close to those observed in this study. However, the values (0.53 to 0.78) were higher, justified by the lower CI values obtained in their evaluation. Fox \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e highlighted km values ranging from 0.576, for diets with ME of 2.0 Mcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (temperate climate grasses in late flowering), 0.651 for diets with ME of 2.6 Mcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (corn forage), and up to 0.686, for diets with ME of 3.2 Mcal kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (corn grains).\u003c/p\u003e \u003cp\u003eThe methane emissions observed in this study agree with the results observed by Machado \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e for sorghum silage and McGeough \u003cem\u003eet al\u003c/em\u003e.\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e for corn silage harvested at different maturity stages. The increase in starch concentration, accompanied by a decline of fibrous constituents, can alter rumen fermentation, favoring the production of propionic acid and resulting in a decline in methane formation\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e,\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u003c/sup\u003e. Hatew \u003cem\u003eet al.\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e suggested that late harvesting of corn could be an effective strategy to reduce methane production in dairy cows without negatively impacting their performance. Ruminants fed diets high in fiber and low in NFC can increase methane emissions\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Consequently, these animals present lower performance and a longer production cycle\u003csup\u003e\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e,\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e\u003c/sup\u003e, compromising the sustainability of production systems\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn this study, despite the nutritional changes observed in silage produced from plants at different stages of maturation, these were not significant enough to affect methane production by the animals. This lack of effect could possibly be attributed to the fact that the sheep used in the study were in a maintenance situation (low nutritional demand). However, modifications in the nutritional value of forage could potentially yield different results in animals with high nutritional demands, such as growing sheep and lactating cows\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan additionalcitationids=\"CR58\" citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe \u0026lsquo;BRS 610\u0026rsquo; sorghum should be harvested for silage production when the plants have grains in the hard dough stage. This stage ensures the production of roughage with higher energy values, improved voluntary intake, digestibility, and efficiency in nitrogen utilization, without adversely affecting methane production by animals.\u003c/p\u003e \u003cp\u003eA practical implication to be considered is the processing of sorghum grains at harvesting. Improper processing can compromise the nutritional value of the silage, particularly the availability of energy for the animal.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAuthor contributions: J.P.S.R. Writing - original draft, writing - review \u0026amp; editing, W.S.A. Data curation, writing - original draft, writing - review \u0026amp; editing. All authors (Marielly Maria Almeida Moura, Jo\u0026atilde;o Paulo Santos Roseira, Wagner Sousa Alves, Otaviano de Souza Pires Neto, Edson Hiydu Mizobutsi, Daniel Ananias de Assis Pires, Ren\u0026ecirc; Ferreira Costa, Cinara da Cunha Siqueira Carvalho, Irisl\u0026eacute;ia Pereira Soares de Sousa, Martielle Batista Fernandes, Luciele Barboza de Almeida, Sabrina Gon\u0026ccedil;alves Vieira de Castro, Diogo Gonzaga Jayme, L\u0026uacute;cio Carlos Gon\u0026ccedil;alves) reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eWe thank CNPq, CAPES, INCT-CA, and FAPEMIG for their financial support.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data generated or analyzed during this study are included in this published article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSilvestre, A. M. \u0026amp; Millen, D. D. The 2019 Brazilian Survey On Nutritional Practices Provided By Feedlot Cattle Consulting Nutritionists. R. Bras. Zootec 50, 1\u0026ndash;25 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerazzo, A. F. \u003cem\u003eet al.\u003c/em\u003e Agronomic Evaluation of Sorghum Hybrids for Silage Production Cultivated in Semiarid Conditions. Front Plant Sci 8, (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBhattarai, B., Singh, S., West, C. P. \u0026amp; Saini, R. Forage Potential of Pearl Millet and Forage Sorghum Alternatives to Corn under the Water-Limiting Conditions of the Texas High Plains: A Review. Crop, Forage \u0026amp; Turfgrass Management 5, 190058 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNematpour, A., Eshghizadeh, H. R. \u0026amp; Zahedi, M. Comparing the Corn, Millet and Sorghum as Silage Crops Under Different Irrigation Regime and Nitrogen Fertilizer Levels. Int J Plant Prod 15, 351\u0026ndash;361 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRodrigues, P. H. M., Pinedo, L. A., Meyer, P. M., da Silva, T. H. \u0026amp; Guimar\u0026atilde;es, I. C. da S. B. Sorghum silage quality as determined by chemical\u0026ndash;nutritional factors. Grass and Forage Science 75, 462\u0026ndash;473 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLyons, S. E. \u003cem\u003eet al.\u003c/em\u003e Optimal harvest timing for brown midrib forage sorghum yield, nutritive value, and ration performance. J Dairy Sci 102, 7134\u0026ndash;7149 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcDonald, P., Henderson, A. R. \u0026amp; Heron, S. J. E. \u003cem\u003eBiochemistry of Silage\u003c/em\u003e (Marlow Chalcombe Publications, 1991).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLynch, J. P., O\u0026rsquo;Kiely, P. \u0026amp; Doyle, E. M. Yield, quality and ensilage characteristics of whole-crop maize and of the cob and stover components: harvest date and hybrid effects. Grass and Forage Sci 67, 472\u0026ndash;487 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTerler, G., Resch, R., Gappmaier, S. \u0026amp; Gruber, L. Nutritive value for ruminants of different fresh and ensiled sorghum (\u003cem\u003eSorghum bicolor\u003c/em\u003e (L.) Moench) varieties harvested at varying maturity stages. Arch Anim Nutr 75, 167\u0026ndash;182 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHristov, A. N. \u003cem\u003eet al.\u003c/em\u003e SPECIAL TOPICS - Mitigation of methane and nitrous oxide emissions from animal operations: I. A review of enteric methane mitigation options1. J Anim Sci 91, 5045\u0026ndash;5069 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHatew, B., Bannink, A., van Laar, H., de Jonge, L. H. \u0026amp; Dijkstra, J. Increasing harvest maturity of whole-plant corn silage reduces methane emission of lactating dairy cows. J Dairy Sci 99, 354\u0026ndash;368 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLettat, A., Hassanat, F. \u0026amp; Benchaar, C. Corn silage in dairy cow diets to reduce ruminal methanogenesis: Effects on the rumen metabolically active microbial communities. J Dairy Sci 96, 5237\u0026ndash;5248 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArchim\u0026egrave;de, H. \u003cem\u003eet al.\u003c/em\u003e Comparison of methane production between C3 and C4 grasses and legumes. Anim Feed Sci Technol 166\u0026ndash;167, 59\u0026ndash;64 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePires, F. P. A. de A. \u003cem\u003eet al.\u003c/em\u003e Effect of the \u003cem\u003eLactiplantibacillus plantarum\u003c/em\u003e and \u003cem\u003eLentilactobacillus buchneri\u003c/em\u003e on corn and sorghum silage quality and sheep energy partition under tropical conditions. Grass and Forage Science 78, 224\u0026ndash;235 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDi Marco, O. N., Aello, M. S., Nomdedeu, M. \u0026amp; Van Houtte, S. Effect of maize crop maturity on silage chemical composition and digestibility (in vivo, in situ and in vitro). Anim Feed Sci Technol 99, 37\u0026ndash;43 (2002).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBorreani, G., Tabacco, E., Schmidt, R. J., Holmes, B. J. \u0026amp; Muck, R. E. Silage review: Factors affecting dry matter and quality losses in silages. J Dairy Sci 101, 3952\u0026ndash;3979 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu, P., Fu, X., Wang, H., Hou, M. \u0026amp; Shang, Z. Effect of Silage Diet (Sweet Sorghum vs. Whole-Crop Corn) and Breed on Growth Performance, Carcass Traits, and Meat Quality of Lambs. Animals 11, 3120 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSantos, F. P. C. \u003cem\u003eet al.\u003c/em\u003e Re-ensiling effects on sorghum silage quality, methane emission and sheep efficiency in tropical climate. Grass and Forage Sci 76, 440\u0026ndash;450 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFernandes, T. \u003cem\u003eet al.\u003c/em\u003e Effect of amylases and storage length on losses, nutritional value, fermentation, and microbiology of silages of corn and sorghum kernels. Anim Feed Sci Technol 285, 115227 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHill, H., Slade Lee, L. \u0026amp; Henry, R. J. Variation in sorghum starch synthesis genes associated with differences in starch phenotype. Food Chem 131, 175\u0026ndash;183 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWard, G. M., Boren, F. W., Smith, E. F. \u0026amp; Brethour, J. R. Relation between Dry Matter Content and Dry Matter Consumption of Sorghum Silage. J Dairy Sci 49, 399\u0026ndash;402 (1966).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOwens, F. N., Zinn, R. A. \u0026amp; Kim, Y. K. Limits to Starch Digestion in the Ruminant Small Intestine1,2. J Anim Sci 63, 1634\u0026ndash;1648 (1986).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJunges, D. \u003cem\u003eet al.\u003c/em\u003e Short communication: Influence of various proteolytic sources during fermentation of reconstituted corn grain silages. J Dairy Sci 100, 9048\u0026ndash;9051 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoseira, J. P. S. \u003cem\u003eet al.\u003c/em\u003e Effects of exogenous protease addition on fermentation and nutritive value of rehydrated corn and sorghum grains silages. Sci Rep 13, 7302 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFernandes, T., Paula, E. M., Sultana, H. \u0026amp; Ferraretto, L. F. Short communication: Influence of sorghum cultivar, ensiling storage length, and microbial inoculation on fermentation profile, N fractions, ruminal in situ starch disappearance and aerobic stability of whole-plant sorghum silage. Anim Feed Sci Technol 266, 114535 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOba, M. \u0026amp; Allen, M. S. Evaluation of the importance of the digestibility of neutral detergent fiber from forage: Effects on dry matter intake and milk yield of dairy cows. J Dairy Sci 82, 589\u0026ndash;596 (1999).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMiller, M. D. \u003cem\u003eet al.\u003c/em\u003e Influence of fiber degradability of corn silage in diets with lower and higher fiber content on lactational performance, nutrient digestibility, and ruminal characteristics in lactating Holstein cows. J Dairy Sci 104, 1728\u0026ndash;1743 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMertens, D. R. Predicting Intake and Digestibility Using Mathematical Models of Ruminal Function. J Anim Sci 64, 1548\u0026ndash;1558 (1987).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSousa, D. O., Murphy, M., Hatfield, R. \u0026amp; Nadeau, E. Effects of harvest date and grass species on silage cell wall components and lactation performance of dairy cows. J Dairy Sci 104, 5391\u0026ndash;5404 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKerley G C Fahey Jr J M Gould E L Iannotti, M. S. Effects of lignification, cellulose crystallinity and enzyme accessible space on the digestibility of plant cell wall carbohydrates in the ruminant. Food Structure 7, 59\u0026ndash;65 (1988).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCosta, R. F. \u003cem\u003eet al.\u003c/em\u003e In situ degradability of dry matter and fibrous fraction of sorghum silage. Acta Sci 38, 171 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKung, L., Shaver, R. D., Grant, R. J. \u0026amp; Schmidt, R. J. Silage review: Interpretation of chemical, microbial, and organoleptic components of silages. J Dairy Sci 101, 4020\u0026ndash;4033 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSantos, A. C. P. dos \u003cem\u003eet al.\u003c/em\u003e Productive and metabolic parameters, carcass and meat characteristics of lambs fed sorghum silage treated with urea and Lactobacillus buchneri. Livest Sci 251, 104603 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilkins, R. J., Hutchinson, K. J., Wilson, R. F. \u0026amp; Harris, C. E. The voluntary intake of silage by sheep:I. Interrelationships between silage composition and intake. J Agric Sci 77, 531\u0026ndash;537 (1971).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRook, A. J. \u0026amp; Gill, M. Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses. Animal Science 50, 425\u0026ndash;438 (1990).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGebrehanna, M. M., Gordon, R. J., Madani, A., VanderZaag, A. C. \u0026amp; Wood, J. D. Silage effluent management: A review. J Environ Manage 143, 113\u0026ndash;122 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMachado, F. S. \u003cem\u003eet al.\u003c/em\u003e Energy partitioning and methane emission by sheep fed sorghum silages at different maturation stages. Arq Bras Med Vet Zootec 67, 790\u0026ndash;800 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFaria J\u0026uacute;nior, W. G. \u003cem\u003eet al.\u003c/em\u003e Effect of grain maturity stage on the quality of sorghum BRS-610 silages. Arq Bras Med Vet Zootec 63, 1215\u0026ndash;1223 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeixeira, A. de M. \u003cem\u003eet al.\u003c/em\u003e Intake and digestibility of sorghum (Sorghum bicolor, L. Moench) silages with different tannin contents in sheep. R. Bras. de Zootec. 43, 14\u0026ndash;19 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDabiri, N. \u0026amp; Thonney, M. L. Source and level of supplemental protein for growing lambs1. J Anim Sci 82, 3237\u0026ndash;3244 (2004).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaro, C. \u003cem\u003eet al.\u003c/em\u003e Effect of Dietary Crude Protein on Animal Performance, Blood Biochemistry Profile, Ruminal Fermentation Parameters and Carcass and Meat Quality of Heavy Fattening Assaf Lambs. Animals 10, 2177 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlmeida, J. C. S. \u003cem\u003eet al.\u003c/em\u003e Intake, digestibility, microbial protein production, and nitrogen balance of lambs fed with sorghum silage partially replaced with dehydrated fruit by-products. Trop Anim Health Prod 51, 619\u0026ndash;627 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalsamiglia, S., Ferret, A., Reynolds, C. K., Kristensen, N. B. \u0026amp; van Vuuren, A. M. Strategies for optimizing nitrogen use by ruminants. Animal 4, 1184\u0026ndash;1196 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNocek, J. E. \u0026amp; Russell, J. B. Protein and Energy as an Integrated System. Relationship of Ruminal Protein and Carbohydrate Availability to Microbial Synthesis and Milk Production. J Dairy Sci 71, 2070\u0026ndash;2107 (1988).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSouza, C. M. \u003cem\u003eet al.\u003c/em\u003e Lambs fed cassava silage with added tamarind residue: Silage quality, intake, digestibility, nitrogen balance, growth performance and carcass quality. Anim Feed Sci Technol 235, 50\u0026ndash;59 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrito Neto, A. S. \u003cem\u003eet al.\u003c/em\u003e Feed energy utilization by hair sheep: does the 0.82 conversion factor of digestible to metabolizable energy need to be revised? J Agric Sci 161, 734\u0026ndash;742 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSo, S., Cherdthong, A. \u0026amp; Wanapat, M. Growth performances, nutrient digestibility, ruminal fermentation and energy partition of Thai native steers fed exclusive rice straw and fermented sugarcane bagasse with \u003cem\u003eLactobacillus\u003c/em\u003e, cellulase and molasses. J Anim Physiol Anim Nutr (Berl) 106, 45\u0026ndash;54 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWeiss, W. P. Predicting Energy Values of Feeds. J Dairy Sci 76, 1802\u0026ndash;1811 (1993).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlves, W. S. \u003cem\u003eet al.\u003c/em\u003e Effect of new strains of \u003cem\u003eLentilactobacillus buchneri\u003c/em\u003e as inoculants in sorghum silage on the fermentative profile, aerobic stability, and voluntary intake in lambs. New Zealand J of Agri. Res. 1\u0026ndash;17 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, G. Y. \u003cem\u003eet al.\u003c/em\u003e Propionate promotes gluconeogenesis by regulating mechanistic target of rapamycin (mTOR) pathway in calf hepatocytes. Animal Nutrition 15, 88\u0026ndash;98 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGalvani, D. B. \u003cem\u003eet al.\u003c/em\u003e Energy efficiency of growing ram lambs fed concentrate-based diets with different roughage sources. J Anim Sci 92, 250\u0026ndash;263 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFox, D. G. \u003cem\u003eet al.\u003c/em\u003e The Cornell Net Carbohydrate and Protein System model for evaluating herd nutrition and nutrient excretion. Anim Feed Sci Technol 112, 29\u0026ndash;78 (2004).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMc Geough, E. J. \u003cem\u003eet al.\u003c/em\u003e Methane emissions, feed intake, and performance of finishing beef cattle offered maize silages harvested at 4 different stages of maturity1. J Anim Sci 88, 1479\u0026ndash;1491 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSutton, J. D., Cammell, S. B., Phipps, R. H., Beever, D. E. \u0026amp; Humphries, D. J. The effect of crop maturity on the nutritional value of maize silage for lactating dairy cows. 2. Ruminal and post-ruminal digestion. Animal Science 71, 391\u0026ndash;400 (2000).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCardoso, A. S. \u003cem\u003eet al.\u003c/em\u003e Impact of the intensification of beef production in Brazil on greenhouse gas emissions and land use. Agric Syst 143, 86\u0026ndash;96 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCerri, C. E. P. \u003cem\u003eet al.\u003c/em\u003e Reducing Amazon Deforestation through Agricultural Intensification in the Cerrado for Advancing Food Security and Mitigating Climate Change. Sustainability 10, 989 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJonker, A. \u003cem\u003eet al.\u003c/em\u003e Methane emissions changed nonlinearly with graded substitution of alfalfa silage with corn silage and corn grain in the diet of sheep and relation with rumen fermentation characteristics in vivo and in vitro1,2. J Anim Sci 94, 3464\u0026ndash;3475 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Gastelen, S., Dijkstra, J. \u0026amp; Bannink, A. Are dietary strategies to mitigate enteric methane emission equally effective across dairy cattle, beef cattle, and sheep? J Dairy Sci 102, 6109\u0026ndash;6130 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGislon, G. \u003cem\u003eet al.\u003c/em\u003e Milk production, methane emissions, nitrogen, and energy balance of cows fed diets based on different forage systems. J Dairy Sci 103, 8048\u0026ndash;8061 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDetmann, E. \u0026amp; Valadares Filho, S. C. On the estimation of non-fibrous carbohydrates in feeds and diets. Arq Bras Med Vet Zootec 62, 980\u0026ndash;984 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoraes, A. \u003cem\u003eet al.\u003c/em\u003e Effect of application rate of sodium nitrite and hexamine on the fermentation and the chemical composition of guinea grass silage harvested at different stages of maturity. Anim Feed Sci Technol 302, 115667 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRodr\u0026iacute;guez, N. M. \u003cem\u003eet al.\u003c/em\u003e A calorimetry system for metabolism trials. Arq Bras Med Vet Zootec 59, 495\u0026ndash;500 (2007).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlhadas, H. M., Valadares Filho, S. C., Tedeschi, L. O., Vilela, R. S. R. \u0026amp; Souza, G. A. P. In situ evaluation of dried distillers grains (DDG) and of diets containing different levels of DDG inclusion replacing soybean meal, urea and corn, and development of alternative methods to estimate in vivo digestibility of diets. Livest Sci 253, 104706 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFerrero, F., Tabacco, E. \u0026amp; Borreani, G. \u003cem\u003eLentilactobacillus hilgardii\u003c/em\u003e Inoculum, Dry Matter Contents at Harvest and Length of Conservation Affect Fermentation Characteristics and Aerobic Stability of Corn Silage. Front Microbiol 12, 1\u0026ndash;10 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHargrove, J. L. History of the Calorie in Nutrition. J Nutr 136, 2957\u0026ndash;2961 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCavalcanti, A. C. \u003cem\u003eet al.\u003c/em\u003e Parti\u0026ccedil;\u0026atilde;o da energia e produ\u0026ccedil;\u0026atilde;o de metano em ovinos alimentados com feno de Andropogon Gayanus colhido em tr\u0026ecirc;s diferentes idades. Revista de la Facultad de Agronom\u0026iacute;a 118, 102\u0026ndash;113 (2019).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"energy utilization, enteric methane, harvest maturity, respirometry","lastPublishedDoi":"10.21203/rs.3.rs-4523679/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4523679/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe objective of the study was to evaluate the intake, digestibility, energy partition, and methane production of sheep fed with BRS 610 sorghum silage produced from plants harvested at different stages of maturity. Sorghum was harvested at the milk, soft mass, hard mass, and mature stages of development, corresponding to 100, 107, 114, and 121 days after planting, respectively. Twenty uncastrated adult rams were utilized, with five rams per treatment. There was a linear increase in voluntary intake expressed as a function of metabolic weight for dry matter (DM), organic matter (OM), non-fibrous carbohydrates (NFC), and the NDF/CP ratio. The apparent digestibility of DM and OM increased linearly with increasing plant maturity at harvest. The energy content in sorghum silage exhibited a quadratic effect. No significant effect was observed on methane losses, caloric increment (CI), and enteric methane production. BRS 610 sorghum is recommended to be harvested for silage production when the plants reach the hard dough stage. This results in silage with higher energy values, improved voluntary intake, digestibility, and nitrogen use efficiency, without impacting methane production by animals.\u003c/p\u003e","manuscriptTitle":"Effect of maturity stage on sorghum silage production: intake, digestibility, energy partition, and methane production in sheep","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-28 08:30:11","doi":"10.21203/rs.3.rs-4523679/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"de224ad9-b45c-45d7-b92c-9ab2ba5011a6","owner":[],"postedDate":"June 28th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":33737227,"name":"Biological sciences/Plant sciences/Plant physiology"},{"id":33737228,"name":"Biological sciences/Zoology/Animal physiology"}],"tags":[],"updatedAt":"2024-10-09T11:09:12+00:00","versionOfRecord":[],"versionCreatedAt":"2024-06-28 08:30:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4523679","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4523679","identity":"rs-4523679","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}